Flexible circuit assembly and cover for traction inverter system for an electric vehicle

1 . A flexible circuit assembly for a traction inverter system, comprising: a flexible printed circuit body forming an angled shape having an inner side and an outer side, the flexible printed circuit body including: a stiffener region, a trace layer region disposed between a first cover region and a second cover region, the trace layer region including one or more trace layers, and a shield region including a shield layer; a first connector attached to the stiffener region of a first end of the flexible printed circuit body; and a second connector attached to the stiffener region of a second end of the flexible printed circuit body, wherein the trace layer region includes a first trace layer and a second trace layer, and wherein the first trace layer includes a first ground trace routed along the inner side, and a second ground trace routed along the outer side, wherein the first trace layer includes at least one power trace routed proximate to the first ground trace, and signal traces routed between the at least one power trace and the second ground trace.

2 . The flexible circuit assembly of claim 1 , wherein the second connector is oriented substantially perpendicular to the first connector.

3 . The flexible circuit assembly of claim 1 , wherein the first ground trace and the second ground trace have a first width, the power trace has a second width that is less than the first width, and each signal trace has a third width that is less than the second width.

4 . The flexible circuit assembly of claim 3 , wherein the first width is at least two times greater than the second width, and the second width is at least five times greater than the third width.

5 . The flexible circuit assembly of claim 1 , wherein the first trace layer includes at least one additional ground trace layer disposed adjacent to the power trace.

6 . The flexible circuit assembly of claim 1 , wherein the second trace layer is an additional shield layer.

7 . A traction inverter system including a first flexible circuit assembly according to claim 1 , wherein:

the first connector of the first flexible circuit assembly is coupled to a main controller board of the traction inverter system; and

the second connector of the first flexible circuit assembly is coupled to a first motor controller board of the traction inverter system.

8 . The traction inverter system of claim 7 , further including a second flexible circuit assembly according to claim 1 , wherein:

the first connector of the second flexible circuit assembly is coupled to the main controller board of the traction inverter system;

the second connector of the second flexible circuit assembly is coupled to a second motor controller board of the traction inverter system; and

the angled shape of the first flexible circuit assembly has an opposite orientation to the angled shape of the second flexible circuit assembly.

9 . A cover for a traction inverter system, comprising:

an outer surface including:

a central region, a first lateral region, and a second lateral region, and

a constrained layer damping material attached to at least a portion of the central region, at least a portion of the first lateral region, and at least a portion of the second lateral region;

an inner surface including ribs; and

a perimeter configured to be attached to a housing,

wherein the central region, the first lateral region, and the second lateral region form contours that conform to locations of components within the housing, and the constrained layer damping material conforms to the contours.

10 . The cover according to claim 9 , further comprising:

one or more bosses extending from at least one of the central region, the first lateral region, and the second lateral region, each boss defining an opening that is configured to receive a respective fastener; and

one or more towers extending from the constrained layer damping material, each tower aligned above one of the bosses, each tower defining an opening that is configured to receive the respective fastener.

11 . The cover according to claim 9 , wherein the constrained layer damping material includes:

a central region, a first lateral region, and a second lateral region;

a first transition region joining the central region to the first lateral region; and

a second transition region joining the central region to the second lateral region.

12 . The cover according to claim 11 , wherein the first lateral region of the constrained layer damping material includes a third transition region, and the second lateral region of the constrained layer damping material includes a fourth transition region.

13 . The cover according to claim 11 , wherein the constrained layer damping material includes a metal constraining layer, a polymer layer, and at least one adhesive layer to secure the metal constraining layer to the polymer layer.

14 . The cover according to claim 13 , wherein:

the metal constraining layer is sheet steel and has a thickness between 1 mm and 2 mm;

the polymer layer is high-temperature polymer and has a thickness between 1 mm and 3 mm.

15 . The cover according to claim 11 , wherein transition regions conform to the contour between the central region and the first lateral region, and the contour between the central region and the second lateral region.

16 . A traction inverter system, comprising:

a first flexible circuit assembly attached to a main controller board and a first motor controller board;

a second flexible circuit assembly attached to the main controller board and a second motor controller board, wherein each flexible circuit assembly includes:

a flexible printed circuit body forming an angled shape having an inner side and an outer side,

a first connector attached to a first end of the flexible printed circuit body, and

a second connector attached to a second end of the flexible printed circuit body; and

a cover, including:

an outer surface including:

a central region, a first lateral region, and a second lateral region, and

a constrained layer damping material attached to at least a portion of the central region, at least a portion of the first lateral region, and at least a portion of the second lateral region,

an inner surface including ribs, and

a perimeter attached to a housing,

wherein the central region, the first lateral region, and the second lateral region form contours that conform to locations of the first and second flexible circuit assemblies, the main controller board, and the first and second motor controller boards within the housing, and the constrained layer damping material conforms to the contours.

17 . The traction inverter system of claim 16 , wherein the flexible printed circuit body includes:

a stiffener region;

a copper clad laminate (CCL) region disposed between a first cover region and a second cover region, the CCL region including a trace layer that includes a first ground trace routed along the inner side, and a second ground trace routed along the outer side; and

a shield region including a shield layer.

18 . The traction inverter system of claim 16 , wherein:

one or more bosses extend from at least one of the central region, the first lateral region, and the second lateral region, and each boss defines an opening that is configured to receive a respective fastener; and

one or more towers extend from the constrained layer damping material, each tower is aligned above one of the bosses, and each tower defines an opening that is configured to receive the respective fastener.